Microfilm reader/printers have gained universal acceptance as a method for retrieving and making copies of information stored on microfilm. For example, many governmental and legal records are now stored on microfilm, and many libraries store archival newspaper editions on microfilm for compact storage and quick and efficient retrieval. Such storage media allow for large amounts of records and data to be stored in a relatively small space.
The microfilm is stored on reels within relatively compact, generally four inch square cartridges which are approximately 1" deep. A starter leader is attached to the hub of the reel contained within the cartridge and then the microfilm is attached to the starter leader. The microfilm is then wound round the cartridge reel. The free-end of the microfilm is then attached to the tab of a loading leader generally made of polyester. While the starter leader, microfilm, and the tab of the loading leader are all sufficiently narrow to be wound round the hub of the cartridge reel between the opposing radial walls of the reel, the body of the loader leader is of sufficient width so as to rest upon the exterior radial walls of the reel and thus engage the reels on the outside of the reel's radial walls. One end of the cartridge has an opening through which the free-end of the loading leader, and subsequently the microfilm itself, passes to be loaded into the appropriate microfilm reader/printer to allow viewing of the material on the microfilm. By storing the microfilm on a reel which itself is mounted within such a closed cartridge, the microfilm is protected from direct sun light, dust, dirt and excessive handling by the operator.
The cartridge is inserted into the loading cavity of the microfilm reader/printer and the operator then causes the free-end of the loading leader to be automatically loaded onto the take-up reel of the microfilm reader/printer. A loading wheel, generally made of rubber, contacts one edge of the loading leader and presses the loading leader against one of the radial walls of the cartridge reel. The loading wheel rotates, engages the loading leader, and causes the loading leader and cartridge opening reel to rotate so as to expose the free-end of the loading leader which then guides out of the cartridge opening and onto the take-up reel of the reader/printer. The reader/printer take-up reel has radially extending ribs along the interior of its radial walls which frictionally engage the loading leader. The loading wheel and the take-up reel on the reader/printer rotate together such that the free-end of the loading leader is engaged by the reader/printer take-up reel as the loading wheel causes more of the loading leader to be inserted onto the take-up reel. Once enough of the loading leader is sufficiently frictionally engaged by the ribs of the take-up reel to allow further take-up and loading by the take-up reel itself, the operator disengages the loading wheel mechanism.
Most prior art loading leaders are formed of smoothed surfaced, untreated polyester. A prevalent problem with such smooth surface polyester leaders is excessive slippage between the loading wheel and loading leader which makes cartridge loading time consuming. Slippage for such untreated polyester loading leaders can occur up to 50% of the time.
Another prior art loading leader is emulsion treated on one side to increase the frictional engagement between the loading wheel and the loading leader during loading of the microfilm. However, the slippage for these emulsion treated loading leaders still occurs up to 25% of the time. Also, when the loading leaders are initially attached to the microfilm, care must be exercised to ensure that the exposed emulsion side of the leader will be presented to the loading wheel. These emulsion treated loading leaders are manufactured so as to produce a pronounced bow in the loading leader so that the assembler of the microfilm cartridge can distinguish the emulsion side. However, if the bow is not pronounced, the assembler must wet the emulsion treated loading leader to determine the emulsion side so that he or she may properly attach the loading leader to the microfilm during assembly of the cartridge. This increases overall cartridge assembly time, thus increasing cost of assembly.
An object of the present invention is to provide a non-slip film loading leader which virtually eliminates slippage upon loading of the microfilm into a microfilm reader/printer.
It is a further object of the present invention to provide a non-slip film loading leader which may be attached to the microfilm on either surface of the leader and which will still provide a non-slip contact between the loading leader and the loading mechanism of the microfilm reader/printer.
It is also an object of the present invention to provide an economical and efficient process for ultrasonically knurling the loading leaders so as to produce a non-slip surface.